Dinosaur is a animal that lived on Earth millions of years ago. Dinosaur is a wild animal, they are about 12 feet tall and 20 feet long, but some other dinosaurs are taller and some are shorter.No one knows exactly how and why dinosaurs died and disappear from the planet. Some scientists think that there were meteors fired to Earth's surface and destory the dinosaurs, other scientists think that there was too much population or there was no food.Let's hope that human can soon find the answer!